/*
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*
 * OptionHandlerJavadoc.java
 * Copyright (C) 2006 University of Waikato, Hamilton, New Zealand
 */

package weka.core;

import java.util.Enumeration;
import java.util.Vector;

/**
 * Generates Javadoc comments from the OptionHandler's options. Can
 * automatically update the option comments if they're surrounded by the
 * OPTIONS_STARTTAG and OPTIONS_ENDTAG (the indention is determined via the
 * OPTIONS_STARTTAG).
 * <p/>
 * 
 * <!-- options-start --> Valid options are:
 * <p/>
 * 
 * <pre>
 * -W &lt;classname&gt;
 *  The class to load.
 * </pre>
 * 
 * <pre>
 * -nostars
 *  Suppresses the '*' in the Javadoc.
 * </pre>
 * 
 * <pre>
 * -dir &lt;dir&gt;
 *  The directory above the package hierarchy of the class.
 * </pre>
 * 
 * <pre>
 * -silent
 *  Suppresses printing in the console.
 * </pre>
 * 
 * <pre>
 * -noprolog
 *  Suppresses the 'Valid options are...' prolog in the Javadoc.
 * </pre>
 * 
 * <!-- options-end -->
 * 
 * @author fracpete (fracpete at waikato dot ac dot nz)
 * @version $Revision: 1.8 $
 * @see #OPTIONS_STARTTAG
 * @see #OPTIONS_ENDTAG
 */
public class OptionHandlerJavadoc extends Javadoc {

	/** the start comment tag for inserting the generated Javadoc */
	public final static String OPTIONS_STARTTAG = "<!-- options-start -->";

	/** the end comment tag for inserting the generated Javadoc */
	public final static String OPTIONS_ENDTAG = "<!-- options-end -->";

	/** whether to include the "Valid options..." prolog in the Javadoc */
	protected boolean m_Prolog = true;

	/**
	 * default constructor
	 */
	public OptionHandlerJavadoc() {
		super();

		m_StartTag = new String[1];
		m_EndTag = new String[1];
		m_StartTag[0] = OPTIONS_STARTTAG;
		m_EndTag[0] = OPTIONS_ENDTAG;
	}

	/**
	 * Returns an enumeration describing the available options.
	 * 
	 * @return an enumeration of all the available options.
	 */
	public Enumeration listOptions() {
		Vector result;
		Enumeration en;

		result = new Vector();

		en = super.listOptions();
		while (en.hasMoreElements())
			result.addElement(en.nextElement());

		result.addElement(new Option(
				"\tSuppresses the 'Valid options are...' prolog in the Javadoc.",
				"noprolog", 0, "-noprolog"));

		return result.elements();
	}

	/**
	 * Parses a given list of options.
	 * 
	 * @param options
	 *            the list of options as an array of strings
	 * @throws Exception
	 *             if an option is not supported
	 */
	public void setOptions(String[] options) throws Exception {
		super.setOptions(options);

		setProlog(!Utils.getFlag("noprolog", options));
	}

	/**
	 * Gets the current settings of this object.
	 * 
	 * @return an array of strings suitable for passing to setOptions
	 */
	public String[] getOptions() {
		Vector result;
		String[] options;
		int i;

		result = new Vector();

		options = super.getOptions();
		for (i = 0; i < options.length; i++)
			result.add(options[i]);

		if (!getProlog())
			result.add("-noprolog");

		return (String[]) result.toArray(new String[result.size()]);
	}

	/**
	 * sets whether to add the "Valid options are..." prolog
	 * 
	 * @param value
	 *            true if the prolog is to be added
	 */
	public void setProlog(boolean value) {
		m_Prolog = value;
	}

	/**
	 * whether "Valid options are..." prolog is included in the Javadoc
	 * 
	 * @return true if the prolog is printed
	 */
	public boolean getProlog() {
		return m_Prolog;
	}

	/**
	 * generates and returns the Javadoc for the specified start/end tag pair.
	 * 
	 * @param index
	 *            the index in the start/end tag array
	 * @return the generated Javadoc
	 * @throws Exception
	 *             in case the generation fails
	 */
	protected String generateJavadoc(int index) throws Exception {
		String result;
		OptionHandler handler;
		String optionStr;

		result = "";

		if (index == 0) {
			if (!canInstantiateClass())
				return result;

			if (!ClassDiscovery.hasInterface(OptionHandler.class, getInstance()
					.getClass()))
				throw new Exception("Class '" + getClassname()
						+ "' is not an OptionHandler!");

			// any options at all?
			handler = (OptionHandler) getInstance();
			Enumeration enm = handler.listOptions();
			if (!enm.hasMoreElements())
				return result;

			// prolog?
			if (getProlog())
				result = "Valid options are: <p/>\n\n";

			// options
			enm = handler.listOptions();
			while (enm.hasMoreElements()) {
				Option option = (Option) enm.nextElement();
				optionStr = toHTML(option.synopsis()) + "\n"
						+ toHTML(option.description().replaceAll("\\t", " "));
				result += "<pre> " + optionStr.replaceAll("<br/>", "")
						+ "</pre>\n\n";
			}

			// stars?
			if (getUseStars())
				result = indent(result, 1, "* ");
		}

		return result;
	}

	/**
	 * Returns the revision string.
	 * 
	 * @return the revision
	 */
	public String getRevision() {
		return RevisionUtils.extract("$Revision: 1.8 $");
	}

	/**
	 * Parses the given commandline parameters and generates the Javadoc.
	 * 
	 * @param args
	 *            the commandline parameters for the object
	 */
	public static void main(String[] args) {
		runJavadoc(new OptionHandlerJavadoc(), args);
	}
}
